LED street lamp instead of traditional street lamp is a revolution in the field of public utilities because the LED street lamp is well known as saving energy, desirable color, free maintenance, and long service life compared with traditional street lamp. At present, high-power LED street lamp is in the stage of test or trial production, but hardly formally used, although many magnates in illumination industry in the global market have set foot in the field of high-power LED street lamp.
The basic research in high-power LED street lamp has made a breakthrough, for example, A Chinese Patent which has publication Number as(CN1928624A) applied by Tsinghua University discloses a method of designing a 3D optical lens, which provides a kind of immersion lens with low loss and strong phototactic reaction on P.13 of Description and P.8 of Drawings. However, the actual effects of the lens is not perfect, because of the high costs of encapsulation as a primary lens, and the fault of the chips which will lead to scrap with lens and cause the waste accordingly. Moreover, as a secondary lens, when install a secondary lens in front of a LED bulb rigidly usually, the positional error of secondary lens is not avoided as the installing positional error of LED bulb which includes scraping tin, surface mounting, and welding. These will lead to a problem which is the big positional accumulated error of secondary lens relative to LED bulb, thus cause the clearence between LED bulb and secondary lens. Therefore, the problems will increase the optical loss and decrease the performance of lens itself, and the popularization and application of the secondary lens is limited.